Overshoe upper



FIG. 1 is a top and left front perspective view of an overshoe upper showing my new design;

FIG. 2 is a right side elevational view thereof, the left side being a mirror image thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front elevational view thereof; and,

FIG. 5 is a rear elevational view thereof.

The broken line showing of a shoe sole in FIGS. 1-5 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for an overshoe upper, as shown and described. 